Fig. 1 displays the evolution of th

Fig. 1 displays the evolution of the ρ and Hv versus the equidifferent addition of the liquid phase HS. For comparison, the ZrW2O8 sample without liquid addition (liquid content = 0 wt%) is also fabricated under the same sintering parameters. The variation tendencies of both ρ and Hv curves are almost consistent, in which the values increase with the increasing content of the liquid phase. It’s obvious that ρ and Hv increase sharply when the addition of liquid phase is 10 wt% and the trends tend to be constant on the condition of the liquid phase content ≥ 25 wt%. Thereby, the results prove that the liquid phase truly plays a vital role in promoting the densification of the ZrW2O8 fabricated by CSP, and the liquid phase content further controls the effectiveness of the densification when the other sintering parameters are same. From Fig. 1, the liquid phase content of 10 wt% is the inflection point of effective densification, which the densification process of CSP would obviously trigger when the liquid phase content is higher than 10 wt%. Moreover, the saturated densification is achieved with the liquid